When performing cruciate ligament reconstruction, a bone tunnel is formed in the tibia and in the femur so that each end of a ligament replacement graft, for example, a bone-tendon-bone graft, may be inserted into a tunnel and the ligament replacement graft secured between the tibia and the femur. Cruciate ligament reconstruction procedures are described, for example, in U.S. Pat. Nos. Re. 34,871 and 5,562,669, both of which are hereby incorporated herein by reference. A ligament replacement graft may be a patellar tendon, a semitendinosus tendon, or other ligament replacement tissues generally attached to and between a pair of bone blocks, which have been sized for a close fitting engagement within one of the femoral and tibial tunnels. The ligament replacement attached to and between the pair of bone blocks is generally a tendon or a strip of tendon which has been harvested, i.e., stripped of the soft tissues about the periphery of the tendon, and detached from the muscle and the bone, such as the tibia More often than not, however, there is an abundance of soft tissues disposed about the periphery of the tendon, which may make harvesting the tendon a rather slow, difficult and tedious process. In particular, the soft tissues tend to prevent the tendon from being cleanly isolated for detachment from the muscle and bone. Moreover, when attempting to separate the soft tissues from the periphery of the tendon so that a clean strip of tendon may be harvested, there is an increased risk of severing the tendon itself.
Currently, there are several devices adapted for harvesting a tendon or strip of tendon for use in cruciate ligament reconstruction. These tendon harvesting devices are typically designed to separate the soft tissues from the periphery of the tendon by severing the connective tissues between the tendon and the soft tissues. One design provides a patellar tendon harvesting device with a double-bladed scalpel for separating the soft tissues simultaneously along opposite sides of the tendon. However, because the double-bladed scalpel has a cutting surface along the bottom edge of each blade, and separation of the soft tissues from the tendon must be performed by pushing each blade down along each side of the tendon, the sharp blades must be kept substantially parallel to the sides of the tendon to avoid the risk of severing the tendons.
Another design provides a patellar tendon harvesting device with a single cutting blade mounted on a straight handle. The single-bladed device, which has a cutting surface along the bottom edge of the blade, must also be pushed so that the blade moves along the side of the tendon in order to sever the connective tissues between the tendon and the surrounding soft tissues. However, since the instrument is designed with only one blade, a separate cut along each side of the tendon must be performed. In addition, like the double-bladed design, there is nothing between the tendon and the blade of the single-bladed device to protect the integrity of the tendon from being compromised. As a result, when harvesting a tendon or strip of tendon with a single-bladed device, the amount of time, as well as the risk of severing the tendon, may increase.
There are also devices that are designed to harvest a semitendinosus tendon. In general, these devices are cylindrical in shape and are provided with a circular cutting blade at the leading edge. Some may have a slot to permit insertion of the tendon into the circular blade and along the device. Overall, these devices are designed so that the circular cutting blade may be pushed over the tendon to sever the peripheral connective tissues. A few of these devices are designed to rotate as they move over the tendon in order to sever the connective tissues. Of course, if the user is not careful, the sharp circular cutting blade, whether being pushed or rotating, can sever the tendon as it is moved.
To reduce the risk of severing the tendon being harvested, other tendon harvesting devices depend on blunt dissection to sever the connective tissues attaching the soft tissues to the periphery of the tendon. However, because the devices are blunt, the soft tissues may not always be cleanly or efficiently separated from the tendon.